This timeline covers the history of the Transformers Animated cartoon continuity. Note that since the timeframes for some events are given in only vague terms, the exact ordering of portions of the timeline is a "best guess". Also, the Animated units of time "solar cycle" and "stellar cycle" both appear to be rough equivalents of an Earth year.
10 billion years ago
"4 million solar cycles" ago
"A thousand stellar cycles" ago
- Optimus Prime, Sentinel Prime, and Elita-1 explored an alien planet in search of a crashed Decepticon ship and its store of energon. After a battle with giant spiders, the Primes escaped, but Elita One was left behind.
- Seemingly quite some time after the AllSpark was lost, the Great War ended with the Decepticons defeated. 
- A crew of Autobot repairbots led by Optimus Prime working on a damaged space bridge gateway stumbled upon the lost AllSpark. After a battle with Megatron and the Nemesis, their ship crashed to Earth, settling underwater in Lake Erie.
50 years later (22nd century)
- The Autobot repair crew awakened sometime in the 22nd century and became celebrities in the city of Detroit. 
- ↑ Ratchet stated that "We've been around for 10 billion years." It is not made explicit, but from the context it seems as if he was referring to the Transformer race as a whole.
- ↑ There are three references to the war ending "centuries ago" in "Transform and Roll Out, Part 1": two spoken by Ratchet and one by Optimus Prime. It is unclear whether this is an "Earth century" or a Cybertronian one... but Optimus' crew hadn't yet had contact with Earth when these statements were made.
- ↑ Professor Sumdac mentions his updates to Dino Drive's animatronic dinosaurs "bring[s] Dino Drive into the 22nd century."